Affliation: Hayden Planetarium (The American Museum of Natural History)

Astrophysicist Neil deGrasse Tyson is like the cool uncle we wish we had. He mixes esoteric scientific facts with relevant pop culture issues ("If Thor's hammer is made of neutron-star matter, implied by legend, then it weighs as much as a herd of 300-billion elephants") and the result is anything but ordinary. Tyson's Twitter is a must follow.